• Journal of the Korean Magnetic Resonance Society
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• v.21 no.4
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• pp.126-130
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• 2017

In the developed NMR hyperpolarization techniques, Parahydrogen-Induced Polarization (PHIP) technique is widely utilized to overcome the low sensitivity of the NMR/MRI. Parahydrogen generator is essential to produce high spin order of parahydrogen molecule. Commercial parahydrogen generator is well developed with user-friendly systems. However, it has drawbacks of long preparation time (~ 2h including cooling down time of 1h) and high cost (~ 200 million won) for the commercial setup. We designed a simple and portable parahydrogen generating system with low cost (~ 2 million won), which produce polarization in less than 1 min. With the designed parahydrogen generator, we successfully performed the PHIP with Wilkinson's catalyst on styrene. This study will broaden the parahydrogen based polarization transfer study on many researchers by providing the simple portable and low cost parahydrogen generator.

• Korean Journal of Materials Research
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• v.6 no.3
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• pp.318-323
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• 1996

원소 분말을 합성하여 Ti5SI3 화합물을 합성하는 방법을 연구하였다. 합성법으로서는 기본적으로 반응소결법을 사용하였으며, 치밀화를 위하여는 유사-열간 정수압 성형법(PHIP, pseude-hot isostatic pressing)을 사용하였다. 반응소결법에서는 분말의 입도, 반응온도 및 유지시간이 소결밀도에 영향을 주었으며, PHIP법에 의한 치밀화에서는 압력 및 유지 간이 주요 변수로 사용되었다. 이들 변수중 미세한 입도와 유지시간이 기공을 감소시켰다. 또한 Cu의 첨가 영향을 연구하였는데, 약 6wt%이내의 Cu 첨가는 밀도 향상에 좋은 영향을 미쳤다. 반응소결 및 PHIP를 통해 Ti5SI3 -Cu의 상대밀도를 약 99%까지 높일 수 있었으며, 이때 Cu의 효과는 감도지수 부합됨을 확인하였다.

• Journal of the Korean Magnetic Resonance Society
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• v.22 no.1
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• pp.1-9
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• 2018

Among several NMR hyperpolarization techniques, parahydrogen-based hyperpolarization technique is recently extensively utilized to enhance the sensitivity of the conventional NMR/MRI spectroscopy. Two mostly investigated research topics are PHIP (Parahydrogen Induced Polarization) and SABRE (Signal Amplification By Reversible Exchange), which are commonly using the parahydrogen as the source of hyperpolarization. Those researches have been considered as the promising techniques that could provide hyperpolarized states on the ambient substrates including biologically important materials. Therefore, based on their potentials, we briefly reviewed several important experimental results on those topics after introducing the basic principle of parahydrogen and its generation with conceptual explanations. We hope this review will broaden the parahydrogen-based hyperpolarization transfer study on many researches in Korea.

• Journal of the Korean Chemical Society
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• v.57 no.3
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• pp.361-364
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• 2013

A modified synthetic approach to the synthesis of heterocyclic food mutagens, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PHIP) and 2-amino-1,6-dimethylimidazo[4,5-b]pyridine (DMIP) is reported. This route highlights an optimized palladium catalysed Buchwald cross-coupling of 2-halo-1-methyl-imidazo[4,5-b]pyridine with benzophenoneimine followed by acidic hydrolysis to yield compound 7. Using finely tailored conditions, Suzuki cross-coupling reactions with highly efficient catalytic systems were performed as the final step on 8 to introduce the aryl group and methyl group on the heterocyclic core.

• Journal of the Korean Magnetic Resonance Society
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• v.23 no.1
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• pp.6-11
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• 2019

Parahydrogen induced hyperpolarization (PHIP) technique is extensively studied to increase the sensitivity of the conventional NMR spectroscopy and recently try to apply this advanced technique into the revolutionary future of the MRI. The other hyperpolarization technique, which is widely utilized, is DNP (Dynamic Nuclear Polarization)-based hyperpolarization one. Despite its great advances in these fields, it contains several drawbacks to overcome: fast relaxation time, expensive equipment is needed, long build-up time is required (several hours), and batch scale material is hyperpolarized. To overcome all those limitations, one can effectively harness the hyperpolarized spin state of parahydrogen. One important step for utilizing the spin state of parahydrogen is doing well-developed experiments of ALTADENA and PASADENA. Based on those concepts, we successfully obtain the hydrogenation signals of ALTADENA and PASADENA from styrene by using benchtop NMR spectrometer. Also those signals were conceptually analyzed and confirmed with different mechanisms. To our best knowledge, those experiments using 1.4T (benchtop NMR) is the first reported one. Considering these experiments, we hope that parahydrogen-based hyperpolarization transfer studies in NMR/MRI will be broadened in Korea in the future.